Westlake Village, CA (GLOBE NEWSWIRE) - Sienna Biopharmaceuticals, Inc. (NASDAQ:SNNA) today announced that the first patient has been dosed in the Company’s Phase 1/2 proof-of-concept clinical trial of topical product candidate SNA-125 in the treatment of atopic dermatitis and the associated pruritus, or itch. SNA-125 is designed to inhibit Janus kinase 3, or JAK3, and tropomyosin receptor kinase A, or TrkA, with minimal to no systemic exposure. JAK3 is a validated target in atopic dermatitis, psoriasis and pruritus. JAK3 is required for immune cell development, and inhibiting JAK3 blocks the signaling of key cytokines, such as interleukin-4, or IL-4, IL-2 and tumor necrosis factor-alpha, or TNF-α, which results in a reduction in the severity of autoimmune and inflammatory diseases in which those cytokines play a pivotal role. TrkA is the high affinity receptor for nerve growth factor, or NGF, a known mediator of neurogenic inflammation and itch. This multicenter, randomized, double-blind, placebo- and comparator-controlled, intra-individual trial will evaluate the safety, tolerability and efficacy of SNA-125 compared to vehicle and other reference formulations in approximately 30 patients with atopic dermatitis.

“We are pleased to announce that we have now started our SNA-125 proof-of-concept trial for atopic dermatitis,” said Frederick C. Beddingfield III, M.D., Ph.D., President and Chief Executive Officer of Sienna. “This is an important milestone for Sienna, firstly because we have executed on our plan to have five development programs in the clinic within the first half of this year, but also because we have entered an important phase of development for SNA-125, the second product candidate from our Topical by Design™ platform. Because SNA-125 comes from the Topical by Design™ platform, it is designed for highly localized delivery of the drug in the affected skin, with minimal to no systemic exposure. We believe SNA-125 has the potential to be a best-in-class, safe and effective, chronic topical treatment option for atopic dermatitis and look forward to the results from this trial, which we expect to report in the fourth quarter of 2018.”

“Atopic dermatitis is highly prevalent in the United States, dramatically more so than psoriasis,” said Emma Guttman, M.D., Ph.D., Sol and Clara Kest professor of dermatology, vice chair, department of dermatology, Icahn School of Medicine at Mount Sinai and inaugural member of Sienna’s Corporate Advisory Board. “The vast majority of atopic dermatitis patients are children, and parents are highly concerned about side effects from steroid use. Despite new products coming to market for atopic dermatitis, there remains a significant unmet medical need for well-tolerated, safe and effective, non-steroidal treatment options for this population.”

“In this proof-of-concept trial, we are using the validated bilateral atopic dermatitis lesion assay to gain early clinical insight into the safety, tolerability and efficacy of SNA-125 as a topical treatment for atopic dermatitis,” said Paul F. Lizzul, M.D., Ph.D., Chief Medical Officer of Sienna. “There is clear evidence that JAK3 inhibition can significantly reduce the severity of atopic dermatitis and the associated itch. We have demonstrated nonclinically that SNA-125 can meaningfully inhibit JAK3 and other important inflammatory signaling mediators. Now, we are eager to learn and understand how SNA-125 may impact atopic dermatitis patients clinically.”

About Sienna Biopharmaceuticals
Sienna Biopharmaceuticals, Inc. is a clinical-stage biopharmaceutical company focused on bringing innovations in biotechnology to the discovery, development and commercialization of first-in-class, targeted, topical products in medical dermatology and aesthetics. The Company’s objective is to develop an innovative, diversified, multi-asset pipeline of topical therapies that enhance the health, appearance and quality of life of dermatology and aesthetics patients. Sienna is led by a management team with extensive experience in product development and commercialization at several leading dermatology, aesthetics and biotechnology companies. For more information, visit www.SiennaBio.com.

Forward-Looking Statements
This press release contains forward-looking statements, including but not limited to the statements by Sienna’s Chief Executive Officer, Sienna’s Chief Medical Officer and Dr. Emma Guttman and other statements regarding Sienna’s expectations regarding its Phase 1/2 proof-of-concept clinical trials of SNA-125, including the number of patients it anticipates will participate and expected timing related to the studies’ start, completion and data reporting, as well as the potential of SNA-125 to treat atopic dermatitis. Such forward-looking statements involve substantial risks and uncertainties that could cause Sienna’s clinical development programs, future results, performance or achievements to differ significantly from those expressed or implied by the forward-looking statements. Such risks and uncertainties include, among others, the uncertainties inherent in the drug development process, including the clinical trial enrollment process, the regulatory approval processes, the timing of regulatory filings, the challenges associated with manufacturing drug products, Sienna’s ability to successfully protect and defend its intellectual property, and other matters that could affect the sufficiency of existing cash to fund operations and the availability or commercial potential of Sienna’s product candidates. Sienna undertakes no obligation to update or revise any forward-looking statements. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the business of the Company in general, see Sienna’s most recent Quarterly Report on Form 10-Q and any subsequent current and periodic reports filed with the Securities and Exchange Commission.